Method _write

lib/agent.js:539–754

(data, encoding, cb)

    _read(n) {}

    _write(data, encoding, cb) {
      /*
          Messages are of the format:
            uint32                    message length
            byte                      message type
            byte[message length - 1]  message contents
      */
      if (this[SYM_BUFFER] === null)
        this[SYM_BUFFER] = data;
      else
        this[SYM_BUFFER] = concat(this[SYM_BUFFER], data);

      let buffer = this[SYM_BUFFER];
      let bufferLen = buffer.length;

      let p = 0;
      while (p < bufferLen) {
        // Wait for length + type
        if (bufferLen < 5)
          break;

        if (this[SYM_MSGLEN] === -1)
          this[SYM_MSGLEN] = readUInt32BE(buffer, p);

        // Check if we have the entire message
        if (bufferLen < (4 + this[SYM_MSGLEN]))
          break;

        const msgType = buffer[p += 4];
        ++p;

        if (this[SYM_MODE] === ROLE_CLIENT) {
          if (this[SYM_REQS].length === 0)
            return cb(new Error('Received unexpected message from server'));

          const req = this[SYM_REQS].shift();

          switch (msgType) {
            case SSH_AGENT_FAILURE:
              req.cb(new Error('Agent responded with failure'));
              break;
            case SSH_AGENT_IDENTITIES_ANSWER: {
              if (req.type !== SSH_AGENTC_REQUEST_IDENTITIES)
                return cb(new Error('Agent responded with wrong message type'));

              /*
                 byte        SSH_AGENT_IDENTITIES_ANSWER
                 uint32      nkeys

                where `nkeys` is 0 or more of:
                 string      key blob
                 string      comment
              */

              binaryParser.init(buffer, p);

              const numKeys = binaryParser.readUInt32BE();